I see you stumbled onto the biggest problem with Rochester carbs, throttle body wear around the shaft. This can be remedied by bushing the hole and/or increasing the shaft diameter.
If you want to remain with the one bbl, cars of the era had auto choke, and will bolt right on. If you want to go with a 2 bbl progressive, another place to call is Stovebolt Engine Company, Tom sells rebuilt Holley-Weber carbs, refered to here as Pinto carbs.
